/***************************************************************************/
/*                                                                         */
/*  ftsmooth.c                                                             */
/*                                                                         */
/*    Anti-aliasing renderer interface (body).                             */
/*                                                                         */
/*  Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2009 by             */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_OBJECTS_H
#include FT_OUTLINE_H
#include "ftsmooth.h"
#include "ftgrays.h"
#include "ftspic.h"

#include "ftsmerrs.h"


/* initialize renderer -- init its raster */
static FT_Error
ft_smooth_init(FT_Renderer render)
{
    FT_Library library = FT_MODULE_LIBRARY(render);


    render->clazz->raster_class->raster_reset(render->raster,
                                              library->raster_pool,
                                              library->raster_pool_size);

    return 0;
}


/* sets render-specific mode */
static FT_Error
ft_smooth_set_mode(FT_Renderer render,
                   FT_ULong mode_tag,
                   FT_Pointer data)
{
    /* we simply pass it to the raster */
    return render->clazz->raster_class->raster_set_mode(render->raster,
                                                        mode_tag,
                                                        data);
}

/* transform a given glyph image */
static FT_Error
ft_smooth_transform(FT_Renderer render,
                    FT_GlyphSlot slot,
                    const FT_Matrix* matrix,
                    const FT_Vector* delta)
{
    FT_Error error = Smooth_Err_Ok;


    if (slot->format != render->glyph_format)
    {
        error = Smooth_Err_Invalid_Argument;
        goto Exit;
    }

    if (matrix)
        FT_Outline_Transform(&slot->outline, matrix);

    if (delta)
        FT_Outline_Translate(&slot->outline, delta->x, delta->y);

Exit:
    return error;
}


/* return the glyph's control box */
static void
ft_smooth_get_cbox(FT_Renderer render,
                   FT_GlyphSlot slot,
                   FT_BBox* cbox)
{
    FT_MEM_ZERO(cbox, sizeof(*cbox));

    if (slot->format == render->glyph_format)
        FT_Outline_Get_CBox(&slot->outline, cbox);
}


/* convert a slot's glyph image into a bitmap */
static FT_Error
ft_smooth_render_generic(FT_Renderer render,
                         FT_GlyphSlot slot,
                         FT_Render_Mode mode,
                         const FT_Vector* origin,
                         FT_Render_Mode required_mode)
{
    FT_Error error;
    FT_Outline* outline = NULL;
    FT_BBox cbox;
    FT_UInt width, height, height_org, width_org, pitch;
    FT_Bitmap* bitmap;
    FT_Memory memory;
    FT_Int hmul = mode == FT_RENDER_MODE_LCD;
    FT_Int vmul = mode == FT_RENDER_MODE_LCD_V;
    FT_Pos x_shift, y_shift, x_left, y_top;

    FT_Raster_Params params;


    /* check glyph image format */
    if (slot->format != render->glyph_format)
    {
        error = Smooth_Err_Invalid_Argument;
        goto Exit;
    }

    /* check mode */
    if (mode != required_mode)
        return Smooth_Err_Cannot_Render_Glyph;

    outline = &slot->outline;

    /* translate the outline to the new origin if needed */
    if (origin)
        FT_Outline_Translate(outline, origin->x, origin->y);

    /* compute the control box, and grid fit it */
    FT_Outline_Get_CBox(outline, &cbox);

    cbox.xMin = FT_PIX_FLOOR(cbox.xMin);
    cbox.yMin = FT_PIX_FLOOR(cbox.yMin);
    cbox.xMax = FT_PIX_CEIL(cbox.xMax);
    cbox.yMax = FT_PIX_CEIL(cbox.yMax);

    width = (FT_UInt)((cbox.xMax - cbox.xMin) >> 6);
    height = (FT_UInt)((cbox.yMax - cbox.yMin) >> 6);
    bitmap = &slot->bitmap;
    memory = render->root.memory;

    width_org = width;
    height_org = height;

    /* release old bitmap buffer */
    if (slot->internal->flags & FT_GLYPH_OWN_BITMAP)
    {
        FT_FREE(bitmap->buffer);
        slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP;
    }

    /* allocate new one */
    pitch = width;
    if (hmul)
    {
        width = width * 3;
        pitch = FT_PAD_CEIL(width, 4);
    }

    if (vmul)
        height *= 3;

    x_shift = (FT_Int)cbox.xMin;
    y_shift = (FT_Int)cbox.yMin;
    x_left = (FT_Int)(cbox.xMin >> 6);
    y_top = (FT_Int)(cbox.yMax >> 6);

    #ifdef FT_CONFIG_OPTION_SUBPIXEL_RENDERING

    if (slot->library->lcd_filter_func)
    {
        FT_Int extra = slot->library->lcd_extra;


        if (hmul)
        {
            x_shift -= 64 * (extra >> 1);
            width += 3 * extra;
            pitch = FT_PAD_CEIL(width, 4);
            x_left -= extra >> 1;
        }

        if (vmul)
        {
            y_shift -= 64 * (extra >> 1);
            height += 3 * extra;
            y_top += extra >> 1;
        }
    }

    #endif

    #if FT_UINT_MAX > 0xFFFFU

    /* Required check is ( pitch * height < FT_ULONG_MAX ),     */
    /* but we care realistic cases only. Always pitch <= width. */
    if (width > 0xFFFFU || height > 0xFFFFU)
    {
        FT_ERROR(("ft_smooth_render_generic: glyph too large: %d x %d\n",
                  width, height));
        return Smooth_Err_Raster_Overflow;
    }

    #endif

    bitmap->pixel_mode = FT_PIXEL_MODE_GRAY;
    bitmap->num_grays = 256;
    bitmap->width = width;
    bitmap->rows = height;
    bitmap->pitch = pitch;

    /* translate outline to render it into the bitmap */
    FT_Outline_Translate(outline, -x_shift, -y_shift);

    if (FT_ALLOC(bitmap->buffer, (FT_ULong)pitch * height))
        goto Exit;

    slot->internal->flags |= FT_GLYPH_OWN_BITMAP;

    /* set up parameters */
    params.target = bitmap;
    params.source = outline;
    params.flags = FT_RASTER_FLAG_AA;

    #ifdef FT_CONFIG_OPTION_SUBPIXEL_RENDERING

    /* implode outline if needed */
    {
        FT_Vector* points = outline->points;
        FT_Vector* points_end = points + outline->n_points;
        FT_Vector* vec;


        if (hmul)
            for (vec = points; vec < points_end; vec++)
                vec->x *= 3;

        if (vmul)
            for (vec = points; vec < points_end; vec++)
                vec->y *= 3;
    }

    /* render outline into the bitmap */
    error = render->raster_render(render->raster, &params);

    /* deflate outline if needed */
    {
        FT_Vector* points = outline->points;
        FT_Vector* points_end = points + outline->n_points;
        FT_Vector* vec;


        if (hmul)
            for (vec = points; vec < points_end; vec++)
                vec->x /= 3;

        if (vmul)
            for (vec = points; vec < points_end; vec++)
                vec->y /= 3;
    }

    if (slot->library->lcd_filter_func)
        slot->library->lcd_filter_func(bitmap, mode, slot->library);

    #else /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */

    /* render outline into bitmap */
    error = render->raster_render(render->raster, &params);

    /* expand it horizontally */
    if (hmul)
    {
        FT_Byte* line = bitmap->buffer;
        FT_UInt hh;


        for (hh = height_org; hh > 0; hh--, line += pitch)
        {
            FT_UInt xx;
            FT_Byte* end = line + width;


            for (xx = width_org; xx > 0; xx--)
            {
                FT_UInt pixel = line[xx - 1];


                end[-3] = (FT_Byte)pixel;
                end[-2] = (FT_Byte)pixel;
                end[-1] = (FT_Byte)pixel;
                end -= 3;
            }
        }
    }

    /* expand it vertically */
    if (vmul)
    {
        FT_Byte* read = bitmap->buffer + (height - height_org) * pitch;
        FT_Byte* write = bitmap->buffer;
        FT_UInt hh;


        for (hh = height_org; hh > 0; hh--)
        {
            ft_memcpy(write, read, pitch);
            write += pitch;

            ft_memcpy(write, read, pitch);
            write += pitch;

            ft_memcpy(write, read, pitch);
            write += pitch;
            read += pitch;
        }
    }

    #endif /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */

    FT_Outline_Translate(outline, x_shift, y_shift);

    /*
     * XXX: on 16bit system, we return an error for huge bitmap
     * to prevent an overflow.
     */
    if (x_left > FT_INT_MAX || y_top > FT_INT_MAX)
        return Smooth_Err_Invalid_Pixel_Size;

    if (error)
        goto Exit;

    slot->format = FT_GLYPH_FORMAT_BITMAP;
    slot->bitmap_left = (FT_Int)x_left;
    slot->bitmap_top = (FT_Int)y_top;

Exit:
    if (outline && origin)
        FT_Outline_Translate(outline, -origin->x, -origin->y);

    return error;
}


/* convert a slot's glyph image into a bitmap */
static FT_Error
ft_smooth_render(FT_Renderer render,
                 FT_GlyphSlot slot,
                 FT_Render_Mode mode,
                 const FT_Vector* origin)
{
    if (mode == FT_RENDER_MODE_LIGHT)
        mode = FT_RENDER_MODE_NORMAL;

    return ft_smooth_render_generic(render, slot, mode, origin,
                                    FT_RENDER_MODE_NORMAL);
}


/* convert a slot's glyph image into a horizontal LCD bitmap */
static FT_Error
ft_smooth_render_lcd(FT_Renderer render,
                     FT_GlyphSlot slot,
                     FT_Render_Mode mode,
                     const FT_Vector* origin)
{
    FT_Error error;

    error = ft_smooth_render_generic(render, slot, mode, origin,
                                     FT_RENDER_MODE_LCD);
    if (!error)
        slot->bitmap.pixel_mode = FT_PIXEL_MODE_LCD;

    return error;
}


/* convert a slot's glyph image into a vertical LCD bitmap */
static FT_Error
ft_smooth_render_lcd_v(FT_Renderer render,
                       FT_GlyphSlot slot,
                       FT_Render_Mode mode,
                       const FT_Vector* origin)
{
    FT_Error error;

    error = ft_smooth_render_generic(render, slot, mode, origin,
                                     FT_RENDER_MODE_LCD_V);
    if (!error)
        slot->bitmap.pixel_mode = FT_PIXEL_MODE_LCD_V;

    return error;
}


FT_DEFINE_RENDERER(ft_smooth_renderer_class,

                   FT_MODULE_RENDERER,
                   sizeof(FT_RendererRec),

                   "smooth",
                   0x10000L,
                   0x20000L,

                   0, /* module specific interface */

                   (FT_Module_Constructor)ft_smooth_init,
                   (FT_Module_Destructor)0,
                   (FT_Module_Requester)0
                   ,

                   FT_GLYPH_FORMAT_OUTLINE,

                   (FT_Renderer_RenderFunc)ft_smooth_render,
                   (FT_Renderer_TransformFunc)ft_smooth_transform,
                   (FT_Renderer_GetCBoxFunc)ft_smooth_get_cbox,
                   (FT_Renderer_SetModeFunc)ft_smooth_set_mode,

                   (FT_Raster_Funcs*)&FT_GRAYS_RASTER_GET
                   )


FT_DEFINE_RENDERER(ft_smooth_lcd_renderer_class,

                   FT_MODULE_RENDERER,
                   sizeof(FT_RendererRec),

                   "smooth-lcd",
                   0x10000L,
                   0x20000L,

                   0, /* module specific interface */

                   (FT_Module_Constructor)ft_smooth_init,
                   (FT_Module_Destructor)0,
                   (FT_Module_Requester)0
                   ,

                   FT_GLYPH_FORMAT_OUTLINE,

                   (FT_Renderer_RenderFunc)ft_smooth_render_lcd,
                   (FT_Renderer_TransformFunc)ft_smooth_transform,
                   (FT_Renderer_GetCBoxFunc)ft_smooth_get_cbox,
                   (FT_Renderer_SetModeFunc)ft_smooth_set_mode,

                   (FT_Raster_Funcs*)&FT_GRAYS_RASTER_GET
                   )

FT_DEFINE_RENDERER(ft_smooth_lcdv_renderer_class,

                   FT_MODULE_RENDERER,
                   sizeof(FT_RendererRec),

                   "smooth-lcdv",
                   0x10000L,
                   0x20000L,

                   0, /* module specific interface */

                   (FT_Module_Constructor)ft_smooth_init,
                   (FT_Module_Destructor)0,
                   (FT_Module_Requester)0
                   ,

                   FT_GLYPH_FORMAT_OUTLINE,

                   (FT_Renderer_RenderFunc)ft_smooth_render_lcd_v,
                   (FT_Renderer_TransformFunc)ft_smooth_transform,
                   (FT_Renderer_GetCBoxFunc)ft_smooth_get_cbox,
                   (FT_Renderer_SetModeFunc)ft_smooth_set_mode,

                   (FT_Raster_Funcs*)&FT_GRAYS_RASTER_GET
                   )


/* END */